Classify the following reactions as an addition, elimination, ...

Question

Classify the following reactions as an addition, elimination, or substitution:

a. CH₃Br + NaOH → CH₃OH + NaBr

b. H₂C═CH₂ + HCl → CH₃CH₂Cl

c. CH₃CH₂Br → H₂C═CH₂ + HBr

Accepted Answer

All right. Hi, everyone. So this question says to classify the type of organic reaction for each of the given reactions. Here, we have three different reactions to speak of. Now, if I scroll down here, I have four different answer choices. Each proposing different reactions for parts 12 and three, they include addition, elimination substitution and rearrangement. So for this question, I'm going to scroll up one more time to consider all three reactions. And what is changing? Right? When we go from start to finish starting off with our first reaction. Now our first reaction involves an all keen and elemental bro mean. So thats br two combining to create a dye highlight because notice how here we end up with an all kill group that has two halogens. In this case, two bromine atoms attached to adjacent carbons. Hence the term dialing. So the most noteworthy thing here is the fact that bromine is combining with the two carbons of the starting keen to create a larger structure. So essentially bromine is getting added on to the carbons of the all keen to create a larger product. So that indicates that reaction one here is most definitely addition, because we called it an addition reaction involves one compound, adding itself onto an unsaturated reactant specifically in all keen to form a larger saturated product. So that would be part one. Now part two on the other hand involves an ocho hate line reacting with a base, specifically potassium tur betide to produce. And all keep now notice how what's happening in reaction two is essentially the opposite of what's happening in reaction one, right? Because they all kill hide is converted into an all keen and not the other way around. So in order for this to happen, right, our base here has to assist in removing bromine from the carbon chain to produce a double bond and notice the terminology that I am using, right. I'm saying that bromine has to have been removed, it had to have been eliminated. So reaction two is elimination because recall that in an elimination reaction, the starting material loses functional groups or other atoms attached to it that produces an unsaturated product, namely an ache. So bromine got eliminated, right? It got removed and last but not least we have reaction three here. Now, reaction three involves an a bromide reacting with a salt, specifically sodium iodide to produce an och iodide and a bromide salt. So what's taking place in reaction three is a little bit different, right? Because it's not that the anion of our salt is adding onto a double bond and it's not like our bromine is being eliminated to produce an Aine either instead, bromine and iodide are simply switching places right? In the reaction itself, bromine is substituted by iodine on the carbon chain. So naturally reaction three is an example of substitution because iodine simply substituted bro me and there you have it now just for the record because rearrangement is mentioned in some of the answer choices, recall that rearrangement involves producing an isomer of the starting material, right? The number of atoms is not going to change. Rather the connections made between the atoms is what changes to therefore create a different structure with the same amount of atoms. Hence the term isomer. So in this case, that is not quite what's happening here and there you have it right? If I consider all four of my answer choices, then option A is going to be the correct one, right? Because reaction one was addition two was elimination and three was substitution. So with that being said, thank you so very much for watching. And I hope you found this helpful.

Classify the following reactions as an addition, elimination, or substitution:
a. CH₃Br + NaOH → CH₃OH + NaBr
b. H₂C═CH₂ + HCl → CH₃CH₂Cl
c. CH₃CH₂Br → H₂C═CH₂ + HBr

Key Concepts

Addition Reactions

Elimination Reactions

Substitution Reactions

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